Another try to enable katex -- minimum change

[swcurran]

• Enabling katex in the specification
• Temp change to use awhitehead spec-up until a fix is in spec-up

[swcurran]

Retry at enabling katex with a minimum of changes. In doing this, discovered a bug in spec-up that needs to be fixed, so temporarily using @andrewwhitehead 's spec-up repo. Will revert when spec-up PR is merged.

As with the previous try:

@whalelephant -- once this is merged, please look at fixing the latex expressions in Sections 8.1 and 8.3 @TelegramSam @hkny @ArPhil -- please approve this new and improved PR.

[whalelephant]

@swcurran thanks! I have rebased and tested with fixes and updates to key correctness info.

[whalelephant]

@ArPhil

Yep, They are fixed here along with more content. I think what I used before was incorrectly parsed by a local renderer, so best to stick with the package we are using in this PR.

I will rebase everything when this gets merged.

[swcurran]

Merged @whalelephant